Apparatus for heating and cracking oil



Nov. 6, 1934. L.. L. REBBER Er Al.

APPARATUS FOR HEATING AND cRAcxING oIL Filed Jan. 2, 1929 Edward jagaz. BY

Patented Nov. 6, 1934 UNITED STATES 'PATENT ,oFFlcl-:

APPARATUS FOR HEATING AND CRACKING OIL of California Application January 2, 1929, Serial No. 329,752

6 Claims.

This invention relates to a tubular still construction for heating and cracking oil.

The invention will be better understood with reference to the drawing, in which Figure 1 is a plan view of the furnace and Figure 2 is a'section taken on line 2-2 of Figure 1.

1 represents the Walls of the furnace; 2 is the roof; 3 is the bridge Wall; 4 is the re box; 5 is the heating flue; 6 is the burner; 'l is the exit ue; 8 is the stack; 9 is a recirculation pipe; 10 is the recirculation blower; l1 is the recirculation duct; 12 is the recirculation manifold, one on each side of the furnace; 13 are the ue gas injectors positioned across the Wall of the furl" hace, front and back; 14 are dampersin each injector. The tubes in the furnace are positioned across and along the top of the furnace with inletat 15. The oil then passes into a series of banks 18, 18a, 18h, exiting at 19. These banks of tubes are positioned in compartment 5.

The operation of the furnace will be understood from the drawing. The combustion gases generated in 4 pass over the bridge wall 3 and adjacent to tubes 16. The latter are heated mainly by radiant heat and act to coolthe combustion gases so that when they pass over the coils 18, 18a and 18h, they heat them mainly by convection. The temperature of the gases is reduced both by the pre-cooling due to radiation and by injection of ue gases through nozzles 13 so that they are at a temperature where most of the heating which they receive in passing over the tubes 18, 18a and 18h will be below a high radiating temperature. The nozzles 13, since they direct the stream of gases so as to pass over the part of the tubes 16 immediately above the stage 5, act to protect the tube from the high radiant heat of the combustion gases. By cooling the tubes and roof of the furnace they will act to preserve the roof of the furnace which is usually damaged by the high temperature present in furnaces of this nature. The gases passing through nozzle 13a are directed in a stream over the tubes 16 and co-mingled with 5 the gases passing through 4. By so doing they act to blanket the tube 16 to prevent super-heating by the oil and cool the roof of the furnace to prevent deterioration.

While this invention has been described with 50 reference to a furnace as disclosed it is obvious that the same invention may be applied tothe cooling of the Walls of the furnace by directing a stream of cool flue gases over them and if desired, by positioning the tubes on said Walls. The

55 modification will be obvious to those skilled in the art. The term wall as used in the claim shall include the roof. This furnace has additional advantages in cracking to permit the preheating of oil at a relatively high rate and the continued cracking of oil .under mild cracking conditions.

By controlling the amount of gases introduced through nozzles 13 and 13a the temperature and volume of heating gases passing through flue 5 are controlled in such a manner as to obtain an even and mild heating of the oil, to, and at, the desired cracking temperature.

An additional feature of this type of operation is that the preheating of the oil in tubes 16 can be controlled at any rate and the heating of the oil in the cracking sections 18, 18a, 18h, can be controlled ata milder rate independently of the preheating in coils 16 by suitably regulating injectors 13, 13a as will be understood from the above.

l The above disclosure is not to be taken as limiting our invention, but merely as illustrative of our invention, which we claim to be:

1. A furnace comprising a combustion chamber, a bridge wall intermediate the combustion chamber and an enclosing wall of said furnace, tubes over said combustion chamber and over the space between the bridge wall and said furnace wall, tubes in said space, an exit ue, means for recirculating gases directly over the first mentioned tubes' and subsequently over said last mentioned tubes intermingled with fresh combustion gases.

2. A furnace comprising a combustion chamber, a heating chamber, a flue, a series of tubes disposed in said heating chamber, another series of tubes disposed above both. said combustion chamber and said heating chamber, -said last mentioned tubes being disposed in spaced rela-` tionship to said first mentioned tubes in said heating chamber, means for generating fresh combustion gases in said combustion chamber, means for recirculating flue gases from said ue and introducing them directly into contact with and over said second mentioned tubes, means for commingling the fresh combustion gases and recirculated flue gases, means for passing the commingled fresh combustion gases and recirculated gases in contact with said first mentioned tubes disposed in said heating chamber.

3. A furnace comprising a combustion chamber, a heating chamber, a ue, a series of tubes disposed in said heating chamber, another series of tubes disposed above both said combustion chamber and said heating chamber, said last mentioned tubes being disposed in spaced relationship to said first mentioned tubes in said heating chamber, means for generating fresh cornbustion gases in said combustion chamber, means for recirculating flue gases from said flue and introducing them directly into contact with and over said second mentioned tubes, means for passing the fresh combustion gases through the space intermediate said first and second mentioned tubes, means for commingling the recirculated gases with the fresh combustion gases in said intermediate space and means for passing the commingled gases over the first mentioned tubes.

4. A furnace comprising a combustion chamber, a heating chamber, a bridge wall positioned between said combustion chamber and said heating chamber, tubes adjacent the roof of said furnace, said tubes extending over said combustion chamber, bridge wall and heating chamber, an exit iiue, means for recirculating flue gases from said exit ue into direct contact with and over said tubes to blanket the same.

5. A furnace comprising a combustion chamber, front and rear walls, a bridge wall intermediate said front and rear walls of said furnace, tubes adjacent the roof of said furnace, additional ltubes in the space intermediate the bridge wall and the rear wall of said furnace, an exit flue, a plurality of injectors adjacent the roof of said furnace and positioned in said front and rear walls respectively of said furnace and means to pass gases from said flue to said injectors.

6. A furnace comprising a combustion chamber, front and rear walls, a bridge wall intermediate said front and rear walls of said furnace, tubes adjacent the roof of said furnace, additional tubes in the space intermediate the bridge wall and the rear wall of said furnace, an exit flue, a plurality of injectors adjacent the roof of said furnace and positioned in saidfront and rear walls respectively of said furnace, means to pass gases from said flue to said injectors and dampers in said injectors.

LELAND L. REBBER. ALBERT S. CROSSFIELD. EDWARD G. RAGATZ. 

